Some computer systems may use a Virtual Machine (VM) to support a guest operating system or application. Moreover, a VM includes software that runs on a host machine and implements an interface to a guest machine. A virtual machine's guest and the host generally utilize different ISAs (Instruction Set Architectures). Hence, while virtualization may be an important key to energy and cost efficiency (e.g., for cloud computing), the semantics gap between a conventional ISA and a VM guest may create a critical performance issue for virtual machine implementation.